Awareness of Risk Factors for Developing Colorectal Cancer and Effect of Intensive Individualised Dietary Counselling on Improving Nutritional Status and Quality of Life

Author: Zalina Abu Zaid

Abu Zaid, Zalina, 2016 Awareness of Risk Factors for Developing Colorectal Cancer and Effect of Intensive Individualised Dietary Counselling on Improving Nutritional Status and Quality of Life, Flinders University, School of Health Sciences

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Colorectal cancer (CRC) is a highly preventable and yet commonly occurring cancer throughout the world with the highest prevalence in developed countries, and is increasing rapidly in some developing countries such as Malaysia. Key diet and lifestyle (D&L) factors can modulate the risk of developing CRC. Obesity, abdominal fatness, high intakes of red and processed meat and smoking increase CRC risk, whereas higher physical activity (PA) participation and fibre-rich foods reduce the risk.

The aim of this thesis is to investigate the prevalence of D&L risk factors in CRC patients and those at higher risk of developing CRC.

We hypothesised that CRC patients would demonstrate better D&L behaviours and awareness of risk factors than those without CRC but identified elevated risk (inflammatory bowel disease, IBD). In our first study, CRC participants (n = 14) had a higher risk profile compared to IBD (n = 30) (e.g., 80 vs. 30% overweight/obese; 30 vs. 70% sufficiently active). Total knowledge of 15 risk factors was low (47% correct); 60% agreed they were important; and only 11% and 27% had made changes to PA and diet respectively in response to CRC risk. Those with IBD had greater awareness of the role of obesity and higher fibre diets than CRC participants and 50% of the total group (IBD and CRC) wanted more D&L information.

In a second study of 104 older participants (mean age 68 ± 11 years) presenting for bowel resection surgery (non-CRC, n = 23; CRC, n = 81) with a mean Body Mass Index (BMI) of 28.1 ± 5.4 kg/m2, women had better dietary intakes than men but there were no consistent significant differences in dietary intakes according to BMI status or stage of cancer. Overall, 63% had high levels of PA participation but there were no consistent differences between gender, BMI status or stage of cancer.

Malnutrition is common among patients with cancer and it is also associated with negative health outcomes of the patients. Therefore, our third study involved an 8-week randomised controlled trial of intensive D&L counselling with an 8-week follow-up (Intervention group, IG, n = 22) compared to usual practice (Control group, CG, n = 20) in CRC Malaysian participants embarking on their first chemotherapy. In this Malaysian clinic, 67% were malnourished at baseline. The IG showed significant improvements in nutritional status, quality of life, PA levels, some dietary factors and greater readiness to change than the CG. These improvements were sustained 8 weeks after the intervention.

These studies revealed that among CRC participants and those at high risk of CRC, the prevalence of D&L risk factors was high, knowledge was poor, and risk-mitigating behaviours not widely adopted. More information on D&L risk factors should be provided and tailored to different sub-groups, while intensive D&L counselling in CRC patients undergoing chemotherapy may deliver better nutritional outcomes and sustained behaviour changes.

Keywords: Awareness, Risk Factors of Colorectal Cancer, Intensive Individualised Dietary Counselling, Nutritional Status, Quality of Life

Subject: Nutrition thesis, Nutrition and Dietetics thesis

Thesis type: Doctor of Philosophy
Completed: 2016
School: School of Health Sciences
Supervisor: Professor Lynne Cobiac